import Vue from 'vue'
// 导入组件
import ShareFileDialog from './Dialog.vue'
// 使用基础 Vue 构造器，创建一个“子类”
const ShareFileConstructor = Vue.extend(ShareFileDialog)

let shareFileInstance = null
/**
 * 初始化分享文件实例
 * @param {array} fileInfo 要分享的文件数组
 */
const initInstanceShareFile = (fileInfo) => {
  shareFileInstance = new ShareFileConstructor({
    el: document.createElement('div'),
    data() {
      return {
        fileInfo
      }
    }
  })
}
/**
 * 分享文件 Promise 函数
 * @returns {Promise} 抛出确认和取消回调函数
 */
const showShareFileDialog = (obj) => {
  // 非首次调用服务时，在 DOM 中移除上个实例
  if (shareFileInstance !== null) {
    document.body.removeChild(shareFileInstance.$el)
  }
  const { fileInfo } = obj
  return new Promise((reslove) => {
    initInstanceShareFile(fileInfo)
    shareFileInstance.callback = (res) => {
      reslove(res)
      // 服务取消时卸载 DOM
      if (res === 'cancel' && shareFileInstance !== null) {
        document.body.removeChild(shareFileInstance.$el)
        shareFileInstance = null
      }
    }
    document.body.appendChild(shareFileInstance.$el) //  挂载 DOM
    Vue.nextTick(() => {
      shareFileInstance.visible = true //  打开对话框
    })
  })
}

export default showShareFileDialog
